Method and device for realizing steel slag quenching and waste heat recovery by using water and carbon dioxide

Abstract

A method and device for realizing steel slag quenching and waste heat recovery by using water and carbon dioxide, the method is: mixing carbon dioxide and water vapor; the mixed gas is sprayed into a fluidized bed heat exchanger through an injection system, and enters a gas circulation pipeline through a waste heat boiler; Part of the gas is returned to the gas injection system, and the rest is passed into the air distribution plate; the molten metallurgical steel slag is introduced into the fluidized bed heat exchanger for gas quenching, and the generated steel slag particles are suspended under the action of the air flow; the high-temperature gas enters the waste heat boiler for heat exchange to form low-temperature gas Enter the gas circulation pipeline; when the steel slag particles are below 800°C, an exothermic reaction occurs; when the temperature of the high-temperature gas is 450±5°C, supplement CO 2 ; When the material temperature is below 150°C, close the gas injection system; the device includes a steel slag chute, a fluidized bed heat exchanger and a gas injection system. The method of the invention has high utilization efficiency of steel slag waste heat recovery, good steel slag stability, small occupied area, short treatment cycle and low gas consumption.

Description

technical field [0001] The invention belongs to the technical field of iron and steel metallurgy, and in particular relates to a method and a device for realizing steel slag quenching and waste heat recovery by using water and carbon dioxide. Background technique [0002] In recent years, with the rapid development of my country's iron and steel industry, the accumulation of steel slag has increased year by year, which not only occupies a large amount of land, but also causes serious environmental pollution; the energy-saving society has higher and higher requirements for energy saving and consumption reduction of metallurgical enterprises. The development of high-efficiency recovery and utilization technology of metallurgical slag waste heat is an effective and practical energy-saving measure. Efficient and high-quality recovery of metallurgical slag sensible heat will become an important means for iron and steel enterprises to reduce comprehensive energy consumption; Heat is...

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Problems solved by technology

[0006] Poor particle size uniformity of steel slag: The current steel slag treatment processes, such as hot stuffing method, water quenching method, and drum method, have poor particle size uniformity of steel slag after treatment, and low efficiency of steel slag treatment;

[0007] Poor stability of steel slag: The content of unstable calcium oxide in steel slag after the current steel slag treatment process is high, the stability of steel slag is poor, and the utilization rate is low;

[0008] Low-temperature sensible heat in the heat exchange process of steel slag is difficult to use efficiently: the residual temperature of steel slag after recovering steel slag sensible heat in the conventional steel slag treatment process reaches about 300°C, and it is difficult to efficiently utilize low-temperature sensible heat below 300°C;

[0009] Long processing cycle: the traditional hot pouring and stuffy slag process often takes several days to complete

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